1. Field of the Invention
This invention relates to a display apparatus wherein a light emitting device disposed for each pixel is driven by current to display an image and a driving method for the display apparatus and an electronic apparatus using thereof. More particularly, the present invention relates to a driving method for a display apparatus of the active matrix type wherein the amount of current to be supplied to a light emitting device such as an organic EL device is controlled by a field effect transistor of the insulated gate type provided in each pixel circuit.
2. Description of the Related Art
In a display apparatus such as, for example, a liquid crystal display apparatus, a large number of liquid crystal pixels are arrayed in a matrix, and the intensity of transmission light or reflection light of incoming light is controlled for each pixel in response to image information to be displayed to display an image. Although this similarly applies to an organic EL display apparatus wherein an organic EL device is used in each pixel and so forth, the organic EL device is a self-luminous device different from the liquid crystal pixel. Therefore, the organic EL display apparatus is advantageous in that a display image thereof exhibits high visual observability, that no backlight is required and that the response speed is high. Further, the organic EL display apparatus is of the current-controlled type wherein the luminance level or gradation of each light emitting device can be controlled with the value of current to flow therethrough, and is much different in this regard from a display apparatus of the voltage-controlled type such as a liquid crystal display apparatus.
A simple matrix type driving system and an active matrix type driving system are available as a driving system for an organic EL display similarly to an LCD apparatus. Although the former system is simple in structure, it has a problem that it is not suitable to implement a display apparatus of a large size and a high definition. Therefore, development of the latter active matrix type driving system is proceeding energetically. In the active matrix type driving system, the current to flow through a light emitting device in the inside of each pixel circuit is controlled by an active device provided in the inside of each pixel circuit, usually a thin film transistor (TFT). Such an active matrix type driving system is disclosed, for example, in Japanese Patent Laid-Open No. 2003-255856 (hereinafter referred to as Patent Document 1), No. 2003-271095 (hereinafter referred to as Patent Document 2), No. 2004-133240 (hereinafter referred to as Patent Document 3), No. 2004-029791 (hereinafter referred to as Patent Document 4), No. 2004-093682 (hereinafter referred to as Patent Document 5) and No. 2006-215213 (hereinafter referred to as Patent Document 6).